Cell search method, forward link frame transmission method, apparatus using the same and forward link frame structure

A cell search apparatus in an Orthogonal Frequency-Division Multiplexing (OFDM) cellular system in which a unique scrambling code is assigned to each cell, the cell search apparatus comprising:

• a sync acquirer acquiring synchronization of sync channel symbols using a sync channel of a forward link;
• and
• a boundary detector detecting at least one hopping codeword element belonging to a hopping codeword of a target cell from a forward link signal containing sync channel symbols sequence-hopped using the hopping codeword based on the acquired synchronization, and detecting a frame boundary of the target cell based on the detected hopping codeword element,
• wherein the hopping codeword differs from a cyclically-shifted result of the hopping codeword, other hopping codewords used in the system, and cyclically-shifted results of the other hopping codewords.

A forward link frame transmission apparatus of a base station belonging to an Orthogonal Frequency-Division Multiplexing (OFDM) cellular system in which a unique scrambling code is assigned to each cell, the forward link frame transmission apparatus comprising:

• a sync channel generator generating sync channel sequences corresponding to elements of a hopping codeword corresponding to a code group to which a scrambling code of a base station belongs;
• and
• a frame transmitter performing sequence hopping of each sync channel symbol using each generated sync channel sequence, generating an OFDM symbol-based forward link frame containing the sequence-hopped sync channel symbols, and transmitting the generated forward link frame,
• wherein the hopping codeword used in the system differs from a cyclically-shifted result of the hopping codeword, other hopping codewords used in the system, and cyclically-shifted results of the other hopping codewords.

An Orthogonal Frequency-Division Multiplexing (OFDM) cellular system comprising a mobile station and a plurality of base stations, and in which a unique scrambling code is assigned to each cell,

• each of the plurality of base stations comprising:
• a sync channel generator generating a hopping codeword corresponding to a code group to which a scrambling code of the base station belongs and generating sync channel sequences corresponding to elements of the generated hopping codeword;
• and
• a frame transmitter performing sequence hopping of each sync channel symbol using each generated sync channel sequence, generating an OFDM symbol-based forward link frame containing the sequence-hopped sync channel symbols, and transmitting the generated forward link frame, and
• the mobile station comprising:
• a sync acquirer acquiring synchronization of sync channel symbols using a sync channel of a forward link;
• and
• a group detector detecting at least one hopping codeword element belonging to a hopping codeword of a target cell from a forward link signal containing sync channel symbols sequence-hopped using the hopping codeword of the target cell based on the acquired synchronization, and detecting a code group of the target cell based on the detected hopping codeword,
• wherein the detected hopping codeword differs from a cyclically-shifted result of the detected hopping codeword, other hopping codewords used in the system, and cyclically-shifted results of the other hopping codewords.

A cell search method in an Orthogonal Frequency-Division Multiplexing (OFDM) cellular system in which a unique scrambling code is assigned to each cell, the cell search method comprising:

• (a) acquiring synchronization sync channel symbols using a sync channel of a forward link;
• and
• (b) detecting at least one hopping codeword element belonging to a hopping codeword of a target cell from a forward link signal containing sync channel symbols sequence-hopped using the hopping codeword corresponding to a code group to which a scrambling code of the target cell belongs based on the acquired synchronization, and detecting the code group of the target cell based on the detected hopping codeword element,
• wherein the hopping codeword differs from a cyclically-shifted result of the hopping codeword, other hopping codewords used in the system, and cyclically-shifted results of the other hopping codewords.

A cell search method in an Orthogonal Frequency-Division Multiplexing (OFDM) cellular system in which a unique scrambling code is assigned to each cell, the cell search method comprising:

• (a) acquiring synchronization of sync channel symbols using a sync channel of a forward link;
• and
• (b) detecting at least one hopping codeword element belonging to a hopping codeword of a target cell from a forward link signal containing sync channel symbols sequence-hopped using the hopping codeword based on the acquired synchronization, and detecting a frame boundary of the target cell based on the detected hopping codeword element,
• wherein the hopping codeword differs from a cyclically-shifted result of the hopping codeword, other hopping codewords used in the system, and cyclically-shifted results of the other hopping codewords.

A forward link frame transmission method of a base station belonging to an Orthogonal Frequency-Division Multiplexing (OFDM) cellular system in which a unique scrambling code is assigned to each cell, the forward link frame transmission method comprising:

• (a) generating a hopping codeword corresponding to a code group to which a scrambling code of the base station belongs, and generating sync channel sequences corresponding to elements of the generated hopping codeword;
• and
• (b) performing sequence hopping of each sync channel symbol using each generated sync channel sequence, generating an OFDM symbol-based forward link frame containing the sequence-hopped sync channel symbols, and transmitting the generated forward link frame;
• wherein the hopping codeword differs from a cyclically-shifted result of the hopping codeword, other hopping codewords used in the system, and cyclically-shifted results of the other hopping codewords.